Seatbelt system having seamless inflatable member

ABSTRACT

A passenger restraint system ( 100 ) for an occupant of a vehicle ( 102 ) includes an inflatable belt portion comprising a seamless hollow inflatable textile member that becomes inflated upon the occurrence of a collision. The inflatable textile member may vary in size and construction along its length. The belt portion ( 104, 112 ) tightens against the occupant&#39;s body when the inflatable belt portion becomes inflated.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a system for, and method of, providinga seamless inflatable member such as an inflatable bag or seat belt, ina vehicle and inflating the member to protect an occupant when acollision involving the vehicle occurs.

BACKGROUND OF THE INVENTION

[0002] Safety of occupants in vehicles is an important concern tomanufacturers of the vehicles and to the occupants of the vehicles. Themanufacturers have disposed seat belts, some partially or whollyinflatable, and inflatable air bags in the vehicles to protect theoccupants when collisions involving the vehicle occur. An inflatablemember (this term is used herein to describe an air bag as well as aninflatable belt or an inflatable belt portion) becomes inflated upon theoccurrence of a collision involving a vehicle to reduce the occupant'svelocity and deceleration below unacceptable rates and to limit theoccupant's movement to enhance the occupant's safety. Many manufacturershave started to provide inflatable members for occupants of the frontdriver seat of an automobile. Most automobile manufacturers now provide3-point seat belts which include a shoulder belt portion and a lap beltportion. Most aircraft passenger seats are now provided with 2-pointseat belts which include only a lap belt portion. The number of pointsrefers to the number of anchors or retainers that affix the safety beltsystem for an occupant.

[0003] Perhaps the most significant consideration in a vehiclecontaining an inflatable member relates to the fact that such a membercannot begin to restrain the occupant's motion during the vehiclecollision until the occupant has moved into engagement with such member.Air bags that are typically deployed from the dashboard or steeringwheel waste an important portion of the time and deceleration spaceavailable to protect the occupant against injury. This markedly reducesthe occupant's protection from the level that can be provided if therestraint is initiated before the occupant has moved within the vehicleafter initiation of the vehicle collision.

[0004] Non-inflatable seat belts now in use suffer from certainsignificant disadvantages. For example, although certain selecteddesigns of seat belts can, through the use of pre-tensioning devices,begin a restraint of the occupant earlier than the restraint provided byan air bag deployed from the dashboard or steering wheel, such belts donot provide for control of the occupant's head motion. This shorteneddeceleration time, however, has caused markedly higher decelerations andloadings, at least of the occupant's head, and has produced less thandesirable results from the standpoint of injury thereto.

[0005] Seat belts are also often of narrow physical construction andthus have not provided for the distribution of the restraining loadsover wide areas of the occupant's body. This has resulted inunnecessarily high loads being imposed upon the occupant over thelimited portion of the occupant's body in engagement with the seat beltwhen a collision involving the vehicle occurs. Additionally such beltshave possessed an elongation that, in many situations, has allowed thehead of an occupant to strike the steering wheel or the dashboard whenthe occupant has been seated in a front seat.

[0006] Furthermore, the spooling out of the webbing material in the seatbelt and the stretching of the seat belt have contributed to anincreased duration of the unrestrained motion of the occupant before anyeffective restraint. This has meant that the motion of the occupant hashad to be brought to a stop in a shorter time than would have beenpossible if the seat belt had not elongated. This has contributed to theproduction of undesirably high rates of motion and deceleration on theoccupant during the restraint imposed by the seat belt on the movementof the occupant.

[0007] Use of inflatable seat belts of the types known in the prior artdoes not overcome all of the deficiencies and disadvantages discussedabove. Many prior attempts at eliminating these deficiencies anddisadvantages with inflatable belts have included seat belts with a pairof inflatable sections within the belt (one for the shoulder beltportion, the other for the lap belt portion) and have additionallyrequired the inflation of these sections to be accomplished by largerthan desirable inflators. Many previous attempts at producingsatisfactory inflatable belts have also resulted in serious problemswith storing the pair of inflatable sections in the vehicle and haverequired these inflatable sections to occupy areas that interfere withentrance and egress of the occupant respectively into and from thevehicle.

[0008] The deficiencies and disadvantages of many prior art inflatableseat belts have also required the inflators to be positioned at thereleasable coupling member and the retainer to be positioned at thesides of the seats. This duality of inflatable sections has caused manysignificant problems. One of these has been that the inflatable gaseshave had to pass through conduits located at the buckle attachment pointof the belts that are in themselves releasable. This makes the belts andthe inflator difficult to package and to operate.

[0009] The inflatable belts with dual inflatable sections have had to beattached to mechanisms which allow for variable lengths of the belts tobe deployed due to variable sizes and positions of the occupants withinthe vehicle. This has required the inflator to be located at the bucklelocation with the aforementioned deficiencies or has required the heavymass of the inflator to be contained within the inflatable sections ofthe seat belts. Furthermore, the duality of inflatable sections hasrequired additional inflators, squibs, wiring and the like to be usedsince both of the inflatable sections in the pair have had to besimultaneously inflated.

[0010] Most inflatable seat belts known in the prior art have othersignificant deficiencies and disadvantages. For example, they do notadequately protect the occupant's neck and head in a side collision.Furthermore, they also do not adequately protect the occupant's lowerextremities. This results from the fact that the front seat occupant'slower extremities tend to slide forward against the instrument panel atthe time of the collision while the occupant in the rear seat tends toslide against the rear of the front seat. This “submarining” has causedthe occupants to incur injuries to the lower extremities.

[0011] The inflators associated with most prior inflatable seat beltshave operated in an inefficient thermodynamic manner, and thus haverequired relatively large amounts of pyrotechnic materials to beprovided in the inflators so that the size and weight of the inflatorshave had to be increased to undesirable proportions. The amount of thepyrotechnic material required in most of the inflators of the prior arthas been roughly between fifty percent (50%) to one hundred percent(100%) more than is used in the preferred inflator of this invention. Asa result, acceptable packaging of most prior art inflatable belts andthe inflator within a vehicle has been precluded.

[0012] The configuration and composition of the combustible materialsused in most existing inflators have also produced relatively slowinflation systems. These slow inflation systems, while useful for airbags, have not been useful for inflatable seat belts since suchrestraints must deploy in less than one fourth of the time for thedeployment of a typical air bag, to be effective, particularly toprovide occupant protection from side impacts. The deceleration distanceof a vehicle involved in a side collision and the time interval betweenthe initiation of the side impact against the vehicle and the strikingof the occupant against an interior vehicle surface are greatly reducedrelative to the distance and time for a front impact.

[0013] The combustible materials for some of these known systems havealso required filters to collect the solid particulates that areproduced in operation. Other known systems have utilized pyrotechnicgrains of such size that grain fracture and cracking have occurred andhave caused variations in the combustion surface, thereby detrimentallyaffecting the burning rates within the grains and hence the inflationtime Furthermore, when large grains have been utilized with slow burningrates, the variations in performance over the range of operatingtemperatures have been undesirably large, resulting in variations inprotection. For example, assuming a 40-50 millisecond function time, thechanges in the burning rate of the pyrotechnic material have caused thefunction time of the inflator to vary by approximately ±20% when thetemperature has been varied between 175° F. and −65° F. Thisconsiderable percentage change in the burning rate has produced a changein overall function time of approximately 15-20 milliseconds, anappreciable portion of the time available to an air bag to deceleratethe movement of the occupant, given that a typical frontal impact of anautomobile lasts only about 120 milliseconds.

BRIEF DESCRIPTION OF THE INVENTION

[0014] This invention provides a system which overcomes the abovedisadvantages and deficiencies. It comprises a seat belt combining aseamless hollow inflatable belt portion disposed across and adjacent theoccupant's body which becomes tightened against the occupant's body whenthe inflatable portion becomes inflated. “Hollow” as used herein inreference to a textile structure means that such structure is capable ofbeing inflated. In a first preferred embodiment, it comprises a 3-pointseat belt combining a seamless generally tubular inflatable shoulderbelt portion disposed across and adjacent the occupant's chest, neck andhead and an interconnected lap belt portion which becomes tightenedagainst the occupant's lap when the inflatable portion becomes inflated.In a second preferred embodiment, it comprises a 2-point seat belthaving a seamless generally tubular inflatable belt portion disposedacross and adjacent the occupant's lap which becomes tightened againstthe occupant's lap and extends upward toward the occupant's chest whenthe inflatable portion becomes inflated. Either of these enhancedrestraints prevent the occupant in a front seat from sliding against theinstrument panel or the steering wheel at the time of vehicular impact,thereby protecting against injury to the occupant's knees and lowerextremities. Either of these enhanced restraints also prevents theoccupant in a rear seat from sliding against the back of a front seat.

[0015] Furthermore, in the first embodiment that includes an inflatableshoulder belt portion, when inflated, the inflatable generally tubularbelt portion shortens in effective length and displaces away from thechest of the occupant to provide, in combination, pretensioning of theinflatable belt portion, load distribution and a support cushion for thehead in frontal collision. Additionally, by passing the inflatable beltportion across the shoulder and alongside the head, the inflatablegenerally tubular belt portion protects the occupant's neck and headfrom injury due to side impact.

[0016] An suitable inflator which responds almost instantaneously when acollision involving the vehicle occurs is described in WO 97/23367published Jul. 3, 1997, entitled “Inflatable Seat Belt System”, namingDonald J. Lewis as inventor, which is incorporated herein by reference.For example, the inflator provides for the inflation of the inflatablebelt portion in approximately ten milliseconds (10 ms) after beingtriggered by the vehicle collision. This is enabled in part by the useof a small pressure volume of approximately two (2) cubic inches in theinflator. This inflator is adapted for use with small particles of apyrotechnic material, which provide a large surface that enhances theburning rates of such particles to provide for gas generation rates upto approximately ten (10) times greater than that of the inflators ofthe prior art. Furthermore, the relatively small amount of thepyrotechnic material in this inflator produces a minimal amount of anynoxious by-products or noxious smells. This inflator is furtheradvantageous in that all of the components in the inflator are disposedwithin a housing and in that a gas in the housing flows through a shortoutlet directly into the inflatable belt portion to inflate theinflatable belt portion almost instantaneously after triggering by thevehicle collision.

[0017] The gas flowing through the outlet of the inflator inflates aninflatable belt portion disposed across the occupant's body and attachedto a vehicle support structure (e.g. a pillar behind the occupant'sseat, the floor or a structural seat affixed to the vehicle supportstructure), thereby protecting the occupant's body.

[0018] The inflatable belt portion of this invention may be integrallyformed as by weaving to a webbing defining the remainder of the beltportion, or attached as by multiple stitching to webbing defining theremainder of the belt portion. Some of this stitching may be configuredto become progressively, but not completely, detached to dissipate theforces imposed on the inflatable belt portion when the inflatable beltportion becomes inflated. Where the inflatable belt portion is disposeddiagonally across the chest of the occupant and is joined to a lap beltportion, the lap belt portion is preferably arranged to slideably extendthrough an opening in a coupling member adjacent the inflatable beltportion and laterally across the occupant's lap.

[0019] In such an arrangement the lap belt portion becomes tightenedagainst the occupant's lap when the inflatable belt portion becomesinflated. The lap belt portion is removably attached as by the couplingmember to a retainer at the inner side of the seat. When the couplingmember is detached from the retainer, the lap belt portion becomesdisposed (e.g. wound) on a retractor to dispose the inflatable beltportion near the outboard seat side between the support structure (e.g.the pillar behind the driver's seat) and the retractor. The occupant canthen enter and exit the vehicle without encumbrance. Alternatively, theretractor for the lap belt portion may be connected to the seat itself,and the seat attached to a vehicle support structure, e.g. the floor orframe of the vehicle.

[0020] The inflatable belt portion is preferably enveloped within acover made from any suitable material; for example, a polyester or anylon. The cover may be made from a single piece of material attached atIts opposite ends as by stitching to define a flattened cylinderenveloping the inflatable belt portion. The cover stitchingprogressively separates as the inflatable belt portion becomesprogressively inflated in a direction away from the inflator. The coveris advantageous in that it may designed to assist in providing for acontrolled inflation of the inflatable belt portion in a direction awayfrom the inflator. It also minimizes degradation of the material formingthe inflatable belt portion as from ultraviolet light and protects theinflatable belt portion from degradation as from chafing against theoccupant. A stiffener may be disposed in the cover against theinflatable belt portion to prevent the inflatable belt portion fromtwisting. Alternatively, the cover may be made from a frangible fabricmaterial designed to burst open as the inflatable belt portion isinflated. Alternatively, the inflatable belt portion may contain anintegral stiffener to prevent the inflatable belt portion from twisting.The cover may extend beyond the inflatable belt portion to define theremainder of the belt portion in place of standard webbing.

[0021] A switch may be disposed in the retainer in an open position Whenthe coupling member is disposed in the retainer, the switch becomesclosed. The switch is included in an electrical circuit which isoperative to initiate the combustion of the pyrotechnic material withinthe inflator, upon the occurrence of a collision involving the vehicle,when the switch is closed. In this way, the inflatable belt portion canbecome inflated upon the occurrence of a collision involving the vehicleonly when the inflatable restraint system of this invention is connectedto protect the occupant's body. This importantly avoids unnecessarydeployment and attendant replacement costs of repairing a vehicle aftera collision.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In the drawings:

[0023]FIG. 1 is a sectional view of an inflator suitable for use withthe invention, including a frangible container holding particles of apyrotechnic material and including a housing enveloping the containerand holding a gas, for producing thermodynamic energy for inflating aninflatable member such as an inflatable belt portion in a vehicle suchas an automobile or aircraft.

[0024]FIG. 2 is a sectional view similar to that shown in FIG. 1 butshows the inflator after the opening of the container as a result of apartial combustion of the particles of the pyrotechnic material in thecontainer and further schematically shows the continued combustion ofthe pyrotechnic particles in the housing.

[0025]FIG. 3 is a schematic fragmentary perspective view of a vehicleincluding a unitary belt, comprising an inflatable shoulder belt portionand a non-inflatable lap belt portion, adapted to restrain the movementsof an occupant seated in the vehicle in the event of a collisioninvolving the vehicle.

[0026]FIG. 4 is a schematic fragmentary side elevational view of thevehicle and the occupant seated in the vehicle and shows the dispositionof the inflatable shoulder belt portion and the lap belt portion afterthe inflation of the inflatable belt portion.

[0027]FIG. 5 is a fragmentary perspective view of the unitary belt,including the inflatable shoulder belt portion and the lap belt portion,illustrating the attachment of the inflatable belt portion and the lapbelt portion by an arrangement of stitches adapted for dissipating thestresses produced in the inflatable belt portion when the inflatablebelt portion becomes inflated.

[0028]FIG. 6 is a fragmentary sectional view taken substantially on theline 6-6 of FIG. 5 and shows in additional detail the stitchingattaching the inflatable belt portion and the lap belt portion to formthe unitary belt, as well as the folding of the inflatable belt portionto produce a minimal stress on the inflatable belt portion when theinflatable belt portion becomes inflated.

[0029]FIG. 7 is a fragmentary view showing in additional detail thestitching also shown in FIGS. 5 and 6 and illustrating the use of theseat belt stitching in the area where the inflatable belt portionremains folded even after inflation, this stitching being used totransmit loads from the inflatable belt portion to the lap belt portion.

[0030]FIG. 8 is a front elevational view of a seated occupant and showsthe unitary belt, including the inflatable shoulder belt portion and thelap belt portion, in solid lines with the inflatable belt portion andthe lap belt portion restraining the occupant, while showing theinflatable belt portion in broken lines with the inflatable belt portionand the lap belt portion in a non-restraining stowed position.

[0031]FIG. 9 is a sectional view of the inflatable belt portion and acover enveloping the inflatable belt portion and is taken substantiallyon the line 9-9 of FIG. 5.

[0032]FIG. 10 is a side elevational view of a hollow textile having acavity of varying diameter.

[0033]FIG. 11 is a side elevational view of a hollow textile having acavity of varying diameter including warp members that float over theregion of smaller diameter.

[0034]FIG. 12 is an end view schematically depicting production of ahollow textile having a cavity.

[0035]FIG. 13 is a fan-shaped weaving guide for spreading andcontracting the spacing of the warp members.

[0036]FIG. 14 is a stitching pattern for joinder of the inflatable beltportion and another belt portion to form a unitary belt.

[0037]FIG. 15 is a side elevational cutaway view of an inflatable beltincluding a three-layer seamless hollow textile structure.

[0038]FIG. 16 is fragmentary perspective view of an inflatable beltincluding a three-layer seamless tubular textile structure.

[0039]FIG. 17 is a schematic view of a weaving pattern for an inflatabletextile structure, the pattern being visible when the textile structureis severed parallel to the warp direction.

[0040]FIG. 18 is a schematic view of a weaving pattern for an inflatabletextile structure, the pattern being visible when the textile structureis severed perpendicular to the warp direction.

[0041]FIG. 19 is a side elevational view of a seamless inflatabletextile (shown in its inflated state) of varying diameter.

[0042]FIG. 20 is a side elevational view of a seamless inflatabletextile (shown in its inflated state) for an inflatable belt system.

[0043]FIG. 21 is a fragmentary front elevational view of a seatedoccupant and shows another embodiment of a unitary belt, including theinflatable belt portion as the lap belt portion restraining theoccupant.

[0044]FIG. 22 is a side elevational view of a seamless inflatabletextile (shown in its inflated state) for an inflatable belt system, insolid lines at normal inflation pressure, and in dashed lines afterexposure to excess internal gas pressure.

[0045]FIG. 23 is a schematic view of an apparatus for weaving a seamlesshollow textile structure.

DETAILED DESCRIPTION OF THE INVENTION

[0046] The invention will first be described in reference to the unitarybelt indicated generally at 100 (FIGS. 3 and 4). Thereafter, theinvention will be described in reference to the unitary belt indicatedgenerally at 160 (FIG. 21).

[0047] One embodiment of an apparatus (an inflator) for inflating aninflatable member such as an inflatable belt portion is generallyindicated at 10 in FIGS. 1 and 2. In the embodiment of the inflator 10shown in the drawings, a housing 12 is provided. The housing 12 may bemade from a material with a low thermal conductivity to serve as apressure vessel for holding a gas, preferably an inert gas such asnitrogen, helium or argon. Argon is the preferred gas. The gas may beinserted into the housing 12 through a hollow pin 14 which may be closedas by welding after the gas has been inserted into the housing.

[0048] The housing 12 may be crimped as at 16 to hold an insert 18preferably having a low thermal conductivity. The housing 12 and theinsert 18 may be formed from a metallic material preferably of a towthermal conductivity or from a material with an interior surface coatingof a low thermal conductivity. The housing 12 and the insert 18 may alsobe formed from an epoxy, fiber glass, nylon or a number of othersuitable materials having a low thermal conductivity, all which are wellknown in the art. A ring 19 is disposed in the housing 12 adjacent thecrimp 16 to provide a seal for preventing gas leakage from the housing.

[0049] A switch 20 may be disposed in the insert 18. A diaphragm 22 maybe pressed against the switch 20 when the pressure of the gas in thehousing 12 exceeds a predetermined value. When the pressure of the gasin the housing 12 becomes less than such predetermined value, thediaphragm 22 becomes displaced from the switch 20. The switch 20 thenbecomes closed to illuminate a light on the instrument panel or displaypanel (not shown) at the front of the occupant compartment in thevehicle, thereby indicating that the inflator 10 is not operative. Theoperation of the switch 20 may provide a signal to associated electroniccircuitry. This signal provides an indication that the inflator 10 is ina defective state. Such associated circuitry is believed to be known toa person of ordinary skill in the art.

[0050] The inflator 10 includes a suitable squib (also known as aninitiator or igniter), which may be constructed as follows. A plug 26may be made from a material having a low thermal conductivity.Preferably the plug 26 has the same composition as the material of theinsert 18. Connector pins 24 extend into the plug 26. The connector pins24 are connected electrically to a bridge wire 28. The bridge wire 28 ispreferably coated or in direct juxtaposition with a first firingcompound 29 which is selected to appropriately interface electronicallyand thermally with the electro-thermal characteristics of the bridgewire 28 so as to provide the desired ignition of particles of apyrotechnic material 30. The bridge wire 28 and the first firingcompound 29 are believed to be known in the art. The particles of thepyrotechnic material 30 are disposed within a frangible container 32 injuxtaposition to the first firing compound 29. The plug 26 electricallyisolates the connector pins 24, one from the other, to preventelectrical shorting. The burning time of the pyrotechnic material 30 maybe between approximately one millisecond (1 ms.) and approximatelythirty milliseconds (30 ms.) and is preferably between approximately twomillisecond (2 ms.) and approximately five milliseconds (5 ms.),depending upon the application.

[0051] The combustible or pyrotechnic material 30 may constituterelatively small particles or granules with a size in the range ofapproximately 0.010 inches to approximately 0.060 inches The particlesmay typically have physical dimensions of approximately 0.050 inch indiameter and approximately 0.20 inch thick or physical dimensions whichare roughly spherical and granular with a sixteen (16) mesh size.

[0052] Material 30 may illustratively constitute particles of a materialdesignated as UPCo 302 or UPCo 718 by Universal Propulsion Company,Phoenix, Ariz., USA. The particles of the pyrotechnic material 30 maycomprise a mixture of different sizes to control the time for thecombustion of the combustible material. When used in the quantitiesrequired for the inflator 10, the material 30 has properties ofproviding by-products when partially combusted, or end products whenfully combusted, that are environmentally safe and that do not produceoffensive or noxious smells when used in the small quantities associatedwith the inflator 10. The term “environmentally safe” as used herein ismeant to indicate that the by-products and end products from thecombustion of the pyrotechnic material 30 do not injure the occupant ordamage the vehicle or the atmosphere.

[0053] The housing 12 may be crimped as at 31 and a ring 34 may beprovided at the crimp to seal the housing to a manifold 36. The ring 34may be affixed to the housing 12 by well-known means other than a crimp.The manifold 36 may be made from a material having a low thermalconductivity and may preferably correspond in composition to the insert18 and the plug 26. A rupturable diaphragm 38 may be disposed across anopening 40 in the manifold 36 to isolate the opening from the housing 12until the diaphragm becomes ruptured. It will be appreciated that othermeans than the diaphragm 38 may be used to isolate the housing 12 fromthe opening 40, and to provide a communication between the housing andthe opening when the gas in the housing expands. For example, aspring-biased pop-off valve may be used instead of the diaphragm 38.

[0054] The opening 40 communicates with a conduit 42 extending from themanifold 36. The conduit 42 is preferably disposed fixedly in themanifold 36 as by a pin 44 or may be rotatably affixed as by a snap ringor by other means known in the art. Alternatively, the conduit 42 may becapable of a relative rotation about its axis to assist in providing themost desirable position for inflating an inflatable belt portion 104(FIG. 4) as the inflatable belt portion passes over the occupant's body.The conduit 42 communicates with the inflatable belt portion 104 (FIG.4). It will be appreciated that the conduit 42 may be omitted if theopening 40 is intended to communicate directly with the inflatable beltportion 104, such as when the inflator is disposed within the inflatablebelt portion (FIG. 21).

[0055] When a collision involving the vehicle occurs, an electricalsignal passes through the connector pins 24 to the bridge wire 28. Thismay be accomplished in a manner well known in the art. The bridge wire28 then becomes heated to ignite the first firing compound 29 which inturn ignites particles of the combustible material 30. The frangiblecontainer 32 becomes opened or ruptured by the heat generated from thecombustion of the particles of the combustible material 30.

[0056] Rupture of the container 32 occurs after a relatively shortperiod of time such as approximately one millisecond (1 ms). After therupture of the container 32, the partially combusted particles of thepyrotechnic material 30 pass into the housing 12 where such particlescontinue to combust. This combustion occurs for a relatively shortperiod of time such as approximately two to five milliseconds (2-5 ms).As shown schematically in FIG. 2, the particles of the pyrotechnicmaterial travel in a direction away from the container 32 toward theopening 40 and combust as they travel in this direction. This causes theparticles of the pyrotechnic material 30 to diminish in size as theytravel from the container 32 toward the opening 40.

[0057] Furthermore, the combustion of the particles of the pyrotechnicmaterial 30 in the housing 12 causes the heat generated by suchcombustion to be transferred directly and thermally to the molecules ofthe gas in the housing 12 without substantial contact with the housing12, the end plug 18 and the manifold 36. The housing 12, the container32, the end plug 18 and the manifold 36 present low thermal conductivitysurfaces to interface with the heated gas, thereby causing the heatliberated from the combustion of the pyrotechnic material to be utilizedeffectively only to heat and expand such gas.

[0058] As previously indicated, the gas in the housing 12 is preferablynitrogen, helium or argon. All limit chemical reaction between thepyrotechnic material 30, or any by-products or end products resultingfrom the combustion of such pyrotechnic material, and such gas. Of theinert gases, argon is preferred because it has a low thermalconductivity. As a result, a substantial portion of the heat generatedby the combustion of the particles of the pyrotechnic material 30 istrapped within the molecules of the argon gas. This heat is used toraise the temperature of the molecules of the argon gas in the housing12. It expands the argon gas in the housing and increases the pressureof the argon gas against the diaphragm 38.

[0059] The frangible container 32 and the housing 12 also co-operate inmaximizing the temperature increase of the gas in the housing 12 as aresult of the heat generated by the particulate combustion. The housing12 and the container 32 are made from low thermal conductivitymaterials, at least on the surfaces in contact with the gas. Suchmaterials may be ceramics, rubber coatings, polyethylene coatings andthe like. These materials have relatively low thermal conductivities ascompared to relatively high thermal conductivity of materials such assteel or aluminum that may be used for the structure of housing 12 andthe container 32.

[0060] The housing 12 and the container 32 also do not absorb anysignificant amount of the generated heat because they are exposed tohigh temperatures only for relatively short periods of time ofapproximately ten milliseconds (10 ms) or less. This is in contrast tomost previously known inflators that function at such elevatedtemperatures for approximately thirty to sixty milliseconds (30-60 ms).During such relatively extended periods of time, significant heat istransferred to the members forming such inflators.

[0061] When the gas has expanded sufficiently in the housing 12, thediaphragm 38 breaks and the gas expands through the opening 40 and theconduit 42. The conduit 42 may be optional. By eliminating the conduit42, the heated gas is transferred directly through the opening 40 to theinflatable belt portion 104. The area of the diaphragm 38 and the crosssection areas of the opening 40 and the conduit 42 may be selected tocontrol the time for the rupture of the diaphragm 38 and the flow of thegas through the opening and the conduit into the inflatable belt portion104. The particular composition of the pyrotechnic material 30 and therelative sizes of the different particles in such material also controlthe time within which the gas is to be heated within the container 32,and accordingly controls the time for the gas to flow into theinflatable belt portion 104.

[0062] The gas flowing through the conduit 42 passes into an inflatablemember such as the inflatable shoulder belt portion 104 which may bemade from a suitable material such as nylon or polyester and may beincluded in a unitary belt generally indicated at 100 (FIGS. 3 and 4).The unitary belt 100 is adapted to be disposed in a vehicle generallyindicated at 102. The unitary belt 100 is constructed to protect anoccupant in the event of a collision involving the vehicle 102. Asillustrated in FIGS. 3 and 4, the inflatable belt portion 104 of theunitary belt 100 is attached at its upper end to a support structuresuch as a pillar 106 which is disposed at the side of the vehicle 102and above a seat 108 which holds the occupant. The pillar 106 isdisposed to the rear of a vehicle door 10 through which the front seatoccupant enters and exits. The support structure may alternatelyconstitute any other suitable portion of the vehicle. For example, thesupport structure may constitute a flange on the inner surface of theroof portion when the inflatable belt portion 104 protects an occupantin the rear seat of the vehicle. As illustrated in FIG. 21, the supportstructure may constitute a structural seat affixed to a structural flooror frame of the vehicle.

[0063] There are numerous ways to provide and position the inflator. Theinflator 10 shown in FIG. 4 is preferably disposed at the upper end ofthe inflatable belt portion 104. When the inflatable belt portion 104 isattached to the pillar 106, this attachment may be at the upper end ofthe pillar 106. The inflatable belt portion 104 may be preferablyintegrated between a decorative fascia with the standard shoulder beltadjustment mechanism enabling the upper position of the inflatable beltportion to fit most favorably the full range of occupants. Theinflatable belt portion 104 is preferably disposed above the occupant'sshoulder and above the occupant's neck and approximately at a horizontallevel approximating the occupant's cheek (left cheek if the occupant isthe driver).

[0064] Alternatively, the inflator may be installed into the webbing andclamped into position away from the largest inflated diameter section ofthe inflatable belt portion. An embodiment of this configuration isillustrated in FIG. 21. As a further alternative, the inflator may bepositioned externally to the inflatable portion of the belt and a portprovided in the belt that is operably connected to the inflator as shownin FIG. 4. The port may be at the end of the inflatable belt portion oralong the length thereof.

[0065] The inflatable belt portion 104 may be folded in a manner asshown in FIG. 6. As shown in FIG. 6, the inflatable belt portion 104 isprovided with a pair of opposed wall portions 104 a and 104 b laterallydisplaced from each other. Each of the wall portions 104 a and 104 bextends in a zigzag configuration from the lateral extremity of suchwall portion to a position intermediate the lateral distance between thelateral extremities of such wall portions. This relationship enhancesthe speed at which the inflatable belt portion 104 in the embodimentshown in FIGS. 3, 4 and 8 can be inflated downwardly from the top of theinflatable belt portion across the chest of the occupant. It alsoenhances the uniformity in the inflation downwardly of the inflatablebelt portion 104. In like manner, the inflatable lap belt portion 160shown in FIG. 21 is preferably folded to enhance the speed anduniformity of the inflation away from the gas generator and across thelap of the occupant.

[0066] A cover 105 (FIG. 9) preferably envelops the inflatable beltportion 104. The cover 105 may be formed from a suitable material suchas polyester and may be provided with a color matching the decor of theinterior of the vehicle 102. The cover 105 may be formed from a singlepiece of material attached at its opposite ends as by stitching 109 Thestitching 109 may be disposed to face the body of the occupant so thatit is not visible to other occupants in the vehicle. The cover 105becomes separated progressively from the inflatable belt portion 104 asthe inflatable belt portion becomes inflated. Preferably a stiffener 107is disposed within the cover 105 against the inflatable belt portion 104to prevent the inflatable belt portion 104 from twisting so that theinflatable belt portion is in a flattened configuration prior toinflation.

[0067] The cover 105 provides several advantages. It prevents theinflatable belt portion 104 from becoming degraded as from ultravioletlight. It also prevents the inflatable belt portion 104 from becomingdegraded as from chafing against the chest of the occupant. Itadditionally holds the inflatable belt portion 104 to a consistentinitial minimal volume and holds the folds of the inflatable beltportion to provide a consistent unfolding of the belt portion during itsinflation. It also reduces the stress on the inflatable belt portion 104as it becomes inflated. The stiffener 107 also assists in retaining thefolds of the inflatable belt portion 104 to provide a consistentunfolding of the belt portion.

[0068] The inflatable shoulder belt portion 104 extends diagonally (at atransverse angle) downwardly to a position near, but above, theoccupant's lap at the inner or inboard side of the occupant's seat 108.In this diagonal or transverse configuration, the inflatable beltportion 104 crosses the occupant's chest. As shown in the embodimentillustrated in FIGS. 5 and 7, at the lower position, the bottom of thelower end of the inflatable belt portion 104 is suitably connected to astandard seat belt webbing material that forms a lap belt portion 112.This may be accomplished by stitching with a reinforcing stitch known asa boxed-X pattern stitch (FIGS. 5 and 7), although other stitches can beused, for example, a curved nine-point diamond pattern stitch (FIG. 14).The lap belt portion 112 may be made from a suitable material such asnylon or polyester. The construction of the lap belt portion 112 maycorrespond to the construction of the lap belts now in use. Theinflatable shoulder belt portion 104 and the lap belt portion 112 may beconsidered to form a unitary belt. Alternatively, in the embodimentshown in FIG. 8, the inflatable shoulder belt portion 104 and the lapbelt portion 112 are integrally formed as by weaving a textile structureas shown in FIGS. 19, 20 or 22. As shown in FIG. 19, the integrallywoven lap belt portion is hollow and inflatable. As shown in FIGS. 20and 22, the integrally woven lap belt portion is flat and not hollow andinflatable. Alternatively, the inflatable belt portion may be attachedby appropriate stitching to a continuation of a tubular textile covermaterial.

[0069] At a position near, but above, the occupant's lap, the lap beltportion 112 extends through a D-ring coupling member 116 (FIG. 8). AD-ring coupling member such as the D-ring coupling member 116 is wellknown in the art. The D-ring coupling member 116 has an opening 115(FIG. 5) through which the lap belt portion 112 extends to change thedirection of the lap belt portion 112 from a downward and transversedirection to substantially a horizontal direction (FIG. 8) in which thelap belt portion extends across the occupant's lap. At its inboard end,the lap belt portion 112 is attached to the D-ring coupling member 116(FIG. 3) that is removably coupled to a retainer 122 in the vehicle. Theconstruction of the D-ring coupling member 116 and the retainer 122 iswell known in the art for use in vehicles such as automobiles now on themarket.

[0070] In the embodiment shown in FIG. 21, the 2-point lap belt isaffixed to a coupling member 116 capable of being detachably attached toretainer 122. The construction of the D-ring coupling member 116 and theretainer 122 is well known in the art for use in vehicles such asautomobiles now on the market.

[0071] The inflatable shoulder belt portion 104 becomes inflateddownwardly from the top of the belt when the inflator 10 is actuated.This is advantageous because it is desirable to exclude the mounting ofthe inflator 10 in undesirable locations such as the buckle andretractor locations due to their attendant gas and electrical connectiondeficiencies. Furthermore, the inflation of the inflatable shoulder beltportion 104 downwardly from the top of the inflatable belt portionfacilitates protection initially of the head, neck and chest of theoccupant. This is advantageous because an injury to the occupant's head,neck and chest can be life ending but an injury to the occupant's lowerextremities such as the occupant's knees and ankles is generally atworst crippling. Furthermore, the case of a side impact of the vehicle102, the time available for interspacing the protective cushion betweenthe head and the interior of the side of the vehicle in a collisionagainst the side of the vehicle is relatively short (e.g. 10-15milliseconds). The downward inflation of the inflatable shoulder beltportion 104 from the top of the inflatable belt portion is particularlybeneficial in such situations.

[0072] As will be seen from FIG. 4, the inflatable shoulder belt portion104, when inflated, protects the occupant's neck and head. This controlsthe occupant's head motion by providing an inflated cushion thatsupports the occupant's head from beneath the chin and prevents theoccupant's head from rotating violently in a forward direction. When theoccupant's head rotates violently forward, as in the prior art,accompanied by a forward movement of the occupant's chest, theoccupant's head may impinge against the dashboard or instrument panel orsteering wheel (when the occupant is in a front seat) unless adequaterestraint against this movement is provided as in this invention.Furthermore, the occupant's neck may be severely strained, as in theprior art, as a result of the violent jerk imparted downwardly to theneck at the time of the collision. It will be appreciated that theinflatable shoulder belt portion of this invention also protects theoccupant's chest and legs. When the occupant is sitting in the rearseat, the occupant's neck and head are protected in this manner by theinflatable belt portion of this invention from moving against the rearof the front seat.

[0073] When the inflatable shoulder belt portion 104 becomes inflated,its effective length is shortened as the path length of the inflatedmaterial in the inflatable belt portion is forced outwardly. This inturn draws the webbing portion of the lap belt portion 112 through theD-ring portion of the coupling member 116 when the coupling member iscoupled to the retainer 122. This causes the lap belt portion 112 tobecome tightened against the lap of the occupant. The lap belt portion112, when tightened by the inflation of the inflatable belt portion 104,restricts the movements of the occupant's lower torso. This inhibits theoccupant's lower body from sliding forwardly and accordinglysignificantly mitigates the chance that the occupant's knees and feetwill be injured. It also positions occupant's upper torso so that theoccupant's head and chest can be most effectively restrained. In likemanner, when the inflatable lap belt portion 160 (FIG. 21) becomesinflated, its length is shortened.

[0074] The amount of the pyrotechnic material 30 in the container 32 isso small and the inflation of the inflatable belt portion 104 is so fastthat the temperature of the inflatable belt portion increases only aminimal amount. For example, the temperature rise of the inflatable beltportion 104, 160 as a result of the inflation of such belt portion maybe approximately only 7 degrees Fahrenheit. This prevents the occupantfrom being burned such as sometimes occurs in the inflatable restraintsof the prior art.

[0075] As shown in FIGS. 5 and 6, the inflatable belt portion 104 isrelatively narrow before inflation. This results from the zigzag foldedconfiguration of each of the wall portions 104 a and 104 b from thelateral extremity of such wall portion to a position intermediate thewall portions. This is shown in FIGS. 5 and 6. However, when theinflatable belt portion 104 becomes inflated, it expands so that thelateral distance between the wall portions 104 a and 104 b becomesconsiderably increased. This is best seen in FIGS. 7 and 8. This isadvantageous since the unit force imposed upon the occupant's body atany position on the chest, neck and head of the occupant's body isconsiderably reduced by the significant increase in the area of contactof the inflatable belt portion 104 against the occupant's body. Theinflatable lap belt portion 160 (FIG. 21) is likewise preferably foldedbefore inflation.

[0076] The lap belt portion 112 is adapted to be coupled to a retractor124 fixedly disposed in the vehicle near the floor of the vehicle.Alternatively, the retractor 124 may be affixed to the floor of thevehicle or the seat. The retractor 124 may be constructed in aconventional manner well known in the art to dispose (e.g. wind) the lapbelt portion 112 on the retractor to allow the unwinding of the lap beltportion from the retractor. Suitable retractors are used with lap beltsin vehicles now on the market. For example, the retractor 124 mayconstitute a Webbing Velocity Sensitive Retractor (Part No. 501580-4031)available from Am-Safe, Inc. of Phoenix, Ariz., USA. This retractor isincorporated by reference in this application.

[0077] The retractor 124 prevents the lap belt portion 12 from beingextended upon the occurrence of a collision involving the vehicle 102.Since the lap belt portion 112 cannot be extended at such a time, theinflation of the inflatable shoulder belt portion 104 produces atightening of the lap belt portion 12 against the lap of the occupant.At the same time, the inflatable shoulder belt portion 104 becomesdisposed adjacent to the occupant's head, neck and chest tosubstantially restrain movement of these portions of the occupant'sbody.

[0078] When the coupling member 116 (FIGS. 3, 5 and 8) is detached fromthe retainer 122 in a manner well known in the art, the retractor 124causes the lap belt portion 104 to become disposed (e.g., wound) on theretractor. As a result, the inflatable belt portion 104 becomes disposeddownwardly to a position adjacent, but to the rear of, the seat 108.This is shown in broken lines in FIG. 8. In the instance where the upperend of the inflatable belt portion 104 is attached to the pillar 106,the occupant is able to enter and exit the vehicle through the frontdoor without any obstruction from any portion of the inflatable belt 104since the pillar is to the rear of the front door. As shown in FIG. 21,when the coupling member 116 is detached from the retainer 122 in amanner well known in the art, the retractor 124 mounted under the seat108 causes the inflatable lap belt portion 160 to be drawn across theseat toward roller guide 103.

[0079] As will be seen, the inflatable belt assembly 100 is advantageousbecause it can be fitted or retrofitted in a vehicle without having toalter any of the components or sub-assemblies in the vehicle. Theunitary belt 100 can be provided for the occupant of the driver's seat,the occupant of the other front seat and the occupants in the rearseats. The unitary belt 100 is provided as an integral assembly in eachof these seats, in part because the inflator 10 for inflating theinflatable belt portion 104 is disposed in juxtaposition to suchinflatable belt portion.

[0080] As will be appreciated from the above discussion, the inflatablebelt portion 104 becomes inflated almost instantaneously after theoccurrence of a collision involving the vehicle. As the inflationreaches the bottom of the inflatable belt portion 104 (the end distalfrom the inflator), it exerts a large stress upon the inflatable beltportion 104, which is believed to be particularly high at the endportion that is last to be filled with gas. While the inventors do notwish to be held to a single theory, it is believed that this stress iscaused by a pulse or shock wave in the inflation gas due to the highvelocity at which it enters and fills the inflatable belt portion. Inthe construction illustrated in FIGS. 5 and 7, this corresponds to thebottom end of the inflatable belt portion 104. which is also theposition of thickness discontinuity between the relatively thin fabricsection of the inflatable belt portion 104 and the thicker portion ofthe webbing of the standard seat belt construction as represented by thelap belt portion 112. This webbing constitutes the material of the lapbelt portion 112. The position of the thickness discontinuity is at theposition where the inflatable belt portion 112 is attached to the lapbelt portion 112.

[0081] Upon inflation, the large stress at the position of the thicknessdiscontinuity between the inflatable belt portion 104 and the lap beltportion 112 may tend to tear the relatively thin material of theinflatable belt portion 104 and separate the inflatable belt portion 104from the lap belt portion 112 if measures were not provided to preventthis from occurring. If the inflatable belt portion 104 became fullyseparated from the inflatable belt portion 112, the desirable effects ofinflating the inflatable belt portion 104 would be lost from thestandpoint of protecting the occupant.

[0082] One way for resolving the problem discussed in the previous twoparagraphs is a stitching arrangement as generally indicated at 130 inFIGS. 5-7. The stitching arrangement includes pluralities 132 a, 132 b,132 c, 132 d and 132 e of stitches 134 arranged in a saw-tooth or zigzagpattern that extends along the end of the belt portion 104 or even intobelt portion 112. As best seen in FIG. 5, the pluralities 132 a, 132 cand 132 e of the stitches 134 have a greater length than the pluralities132 b and 132 d of the stitches 134. The pluralities 132 b and 132 d ofthe stitches 134 are preferably disposed respectively between thepluralities 132 a and 132 c of the stitches 134 and between thepluralities 132 c and 132 e of the stitches 134. It will be appreciatedthat the pluralities of the stitches 134 may have the same or variablelengths. When the inflatable belt portion 104 becomes inflateddownwardly from the upper position of such belt portion, the forceproduced on the thin inflatable cloth constituting the inflatable beltportion 104 at the bottom end of such inflatable belt portion isattenuated as it acts upon progressive ones of the stitches 134 in eachof the pluralities 132 a, 132 b, 132 c, 132 d and 132 e. This actionloads each stitch progressively to the point of separation and therebyprovides for a separation of such stitch. This may be illustrativelyseen in FIG. 7. However, this stitching arrangement is not required inall embodiments of inflatable belt portions; some embodiments exhibitsufficient inherent strength to resist these stresses.

[0083] The large inflation-induced stress at the position of the end ofthe tubular inflatable belt portion 104 where it is joined to the lapbelt portion 112 can alternatively be addressed by provision of thelower end of the inflatable belt portion 104 with an elastomericreinforcement where it is joined to the webbing forming lap belt portion112. The folds adjacent the lower end of the inflatable belt portion 104are coated and adhered to one another with an elastomeric material suchas self-curing silicone. The elastomeric material progressively tearsaway as inflation proceeds, thereby reducing the load on the cloth ofthe inflatable belt portion below that at which the cloth would rupturedue to the inflation gas pulse. However, this elastomeric or siliconereinforcement is not required in all embodiments of continuousinflatable belt portions; some embodiments exhibit sufficient inherentstrength to resist these stresses. In certain embodiments, such anelastomeric reinforcement can be used in combination with other means toresist this large stress.

[0084] At a position removed in the inflatable belt 104 from thepluralities 132 a, 132 b, 132 d, 132 d and 132 e of the stitches 134,additional stitches 136 and 138 (FIGS. 6 and 7) are disposed laterallyacross the widths of the overlapping inflatable belt portion 104 and thelap belt portion 112 at spaced positions along the overlapping lengthsof the inflatable belt portion and the lap belt portion. Additionalstitches extend diagonally from each lateral edge of the stitches 136 tothe other lateral edge of the stitches 138 to define a criss-crosspattern. Such diagonal stitches are indicated at 140 and 142. Thesestitches serve to transmit the loads carried by one lateral edge of theinflatable belt portion 104 along the lateral dimensions of theinflatable belt portion 104 and the lap belt portion 112 to the otherlateral edge of the inflatable belt portion. The combination of stitches136, 138, 140 and 142 may be referred to as a boxed-X stitch.

[0085] The large stress at the lower end of the inflatable belt portion104 can alternatively be addressed by provision of the lower end of theinflatable belt portion 104 as a seamless hollow inflatable member. Incertain preferred embodiments, the one-piece tapered woven textilemaintains continuity as the seamless fabric tapers from a larger size toa smaller size. As the size of the hollow textile becomes smaller, thewarp ends per unit of width (weft direction of the textile) increase,thereby inherently increasing the rupture resistance at the end of thetapered tubular textile. Also, in certain preferred embodiments,selected wefts and optionally selected warps may be formed offilamentary material that is only partially oriented, that is,intentionally not fully drawn and heat set at the time of manufacture.In this latter instance, inflation of the hollow inflatable membercauses these plastically extensible weft ends and warp ends to befurther drawn in the event that the stress due to internal inflationpressure exceeds a threshold value, thereby dissipating the inflationgas energy and pressure that might otherwise rupture the inflatable beltportion 104 or its (sewn) connection to the lap belt portion 112.Selective placement of plastically extensible warp ends can be used toassist in inflation and expansion of the inflatable belt portion awayfrom the body of the occupant. As such partially oriented fibrous memberis drawn, it increases in orientation and strength. In certainapplications, use of partially oriented plastically extensible weftmembers permits manufacture of a tapered tubular woven inflatable beltportion in which the large diameter portion and the small diameterportions are of the same or nearly the same diameter as woven and expandto different diameters when inflated. This simplifies manufacture of theseamless hollow textile for the inflatable belt portion and enablesprovision of an inflatable belt portion that is lighter and lessvoluminous in its uninflated state as compared to prior inflatablerestraint belts.

[0086] At the conclusion of the collision event, it is preferable thatthe inflatable belt portion deflate at least partially to facilitateegress from the vehicle. This may be accomplished through diffusion ofthe inflation gas through the fabric of the inflatable belt portion 104,160 which may be designed to have a specific porosity, or through one ormore vents provided in the inflatable belt portion 104, 160. In allcases, the inflation system provides sufficient gas before and duringthe collision event to inflate and maintain inflation of the inflatablebelt portion 104, 160 sufficient to protect the occupant and when theinflator has exhausted preferably allows deflation in a short time ofseveral seconds.

Manufacture of Tapered Seamless Textile Structure for Use in InflatableBelt Portion

[0087] Suitable seamless hollow textiles for use in inflatable beltportion 104, 160 made be made as follows. Suitable seamless taperedtextiles 60, 70 such as are shown in FIG. 10 and FIG. 11 respectivelyhaving a cavity 61, 71 of changing size or diameter may be manufacturedby weaving a tubular shape as a pair of two-dimensional, layeredsurfaces that are joined at their edges as shown in FIG. 12. A tube 78is woven so as to produce two textile layers 80, 81 lying over eachother in which only the edge regions 82, 84 are woven together. Forthis, the shuttle-weaving technology is especially advantageous, becausethe weft 85 is therefore uncut, alternatingly woven about warps 87 intothe upper textile layer 80 and the lower textile layer 81 andconsequently no seam locations form within the range of the woventubular textile. Also, automatic needle weaving machines like thosemanufactured by Jakob Müller of Frick, Switzerland may be used, thoughthe weft member must be held at the selvedge of the textile, whichresults in a more or less distinct bulge in the warp direction of thetextile.

[0088] Previously known processes for the weaving of tubular structuresgenerate a constant textile width. The diameter of the woven cavity, andthus the woven tube, is therefore constant. In certain embodiments ofthe invention having an inflatable belt portion, however, a hollowtextile is preferred where a more or less strongly tapering diameter orwhere a constant conicity between two different diameters is desired.Tapered cavity textile structures could be produced until now only by aspiral wrapping (filament winding) process or by an interlacing(braiding) process. The spiral wrapping (filament winding) process isvery time consuming and costly and is limited by the danger of movementof the yarn members on the developing core. The interlacing (braiding)process cannot lay yarn members in the circumferential direction of atube. Because the braid yarn members are not laid in the circumferentialdirection, their full strength is not available to the resist hoop(circumferential direction) stress which exists when the textilestructure is inflated. The cavity size can not be changed in acontinuous braiding process, except by passing a mandrel of the desiredpattern through the braiding machine, with the attendant difficulty ofsubsequently removing the mandrel.

[0089] The goal of finding a woven textile structure that forms acavity, e.g. a tubular structure, where the fibrous members proceed inaxial and in circumferential directions, and where the cavity diameteritself increases or reduces in the direction of the warp members may beachieved as described herein below.

[0090] In one embodiment for changing the cavity diameter, as shown inFIG. 10, the spacing of the warps 62 from one another is contracted aswell as spread apart during manufacture of the textile 60. The overallnumber of the warps thus remains constant in the textile 60. The textilewidth changes as the spacing of the warps 62 changes and thus does thediameter of the woven cavity 61.

[0091] In another embodiment for changing of the warp width and thus thecavity width of the textile, as shown in FIG. 11, warps 72 are removedor added as weaving of the textile 70 proceeds. Individual or groups ofwarps are periodically left behind to remain in the high or lowcompartment position of the weaving apparatus while the cavity 71 isbeing woven. These warps 72 float for a distance outside of the surfaceof the woven structure as shown in FIG. 11. At such sites, where thesewarps 72 are tied in again into the textile, the textile width increasesand thus the woven cavity 71 or tube diameter likewise increases. Forthis manufacturing process, it is advantageous to use a jacquard machinewith single warp member control It is also advantageous to use for thesupport of the changing textile width a fan-like weaving reed 90 asshown in FIG. 13 together with a mechanism which catches and positionsthe selvedges of the fabric, or other different equipment that gives thewarps the desired lateral spacing.

[0092] Conventional shuttle weaving technology is especiallyadvantageous for the production of the seamless tubular members havingvariable warp widths. According to conventional weaving technology, thebobbin of weft material and shuttle are together conveyed through theweaving surface as shown in FIG. 12 and, because the weft member 85 isnot severed at the selvedge but is returned and carried back in thefollowing layer, selvedges 82, 84 are formed. The weft member 85 isreturned alternatingly in the upper textile layer 80 and the lowertextile layer 81. The prepared textile 78 has thus a cavity 86 andtubular structure without a seam location since the upper layer 80 turnsat the selvedges 82, 84 without interruption of the lower layer 81turns. Combination of this type of fabric production with one of theproposed warp lateral spacing or width variations provides a seamlesswoven tube with different diameters.

[0093] As an alternative or auxiliary method of manufacture, the widthor size of the textile cavity 61, 71, 86 respectively shown in FIGS. 10,11, 12 may be reduced by increasing the weft member tension which leadsto a constriction of the warp members and thus to a changed textilewidth. It is advantageous in this instance to have an adjustableweft-yarn brake that at certain times brakes the weft yarn more and atother times less.

[0094] In another embodiment of a seamless tubular textile structure,more than two layers can be woven over each other, e.g. three as shownin FIGS. 15 and 16. These embodiments therefore result in two moresuperposed cavities (181, 182 of textile 180 in FIG. 15 and 191, 192 oftextile 190 in FIG. 16) or chambers that proceed in the warp direction.The proposed width-changing techniques described herein also thereforelead to the narrowing or widening of the cavities of the seamlessmultiple cavity tubular textile 180, 190. For use in the inflatable beltportion 104, 160 one or more of the cavities could be connected to thesource of inflation gas. As shown in FIG. 16, at least a portion of oneof the cavities could be formed from warp members of greater strengththan the warp members of the other one of the cavities to providegreater structural capacity. As shown in FIG. 16, portion 193 of thebottom of the bottom cavity 191 is formed of warps 194 that are ofgreater size and strength than the remainder of the warps formingseamless hollow inflatable textile 190. In use in the inflatable seatbelt of this invention, the warp members of greater strength arepositioned against the body (chest or lap) of the occupant, therebyreducing the stress on the thinner material of the inflatable cavity ofthe inflatable belt portion at the position of the thicknessdiscontinuity between the inflatable belt portion 104 and the lap beltportion 112. As shown in FIG. 16, the inflatable belt portion includeswarp members 194 of greater strength and greater resistance toelongation under an imposed tensile load that are positioned tocorrespond to the area of the inflatable belt portion which contacts thebody (chest or lap) of the occupant, thereby preventing undesiredelongation of the unitary belt in a collision in the event thatinflation does not occur or the inflatable portion becomes ruptured.

[0095] In certain preferred embodiments, such as those shown in FIGS. 15and 16, the system is configured to cause the lower chamber 181, 191 ofthe inflatable belt portion to inflate first, and thereafter theinflation gas passes (as indicated by the arrows) from the lower chamber181, 191 through ports 185 (FIG. 15) or porous section 195 (FIG. 16) inthe middle textile layer into the upper chamber 182, 192 to subsequentlyinflate the upper chamber. In use the lower chamber 181 191 ispositioned adjacent the body of the occupant. Sequential inflationbeginning with the lower chamber followed by inflation of the upperchamber serves to more gradually impose a force on the occupant, therebyassisting the occupant to be positioned correctly relative to the seatand the seat belt system as the second chamber is subsequently inflatedto more fully protect the occupant. Use of multiple chambers withsequential inflation allows use of a greater overall chamber sizewithout as great a risk of rupture of the inflatable belt portion orinjury of the occupant due to sudden expansion of the inflatable beltportion. This is particularly of value where the inflatable belt portion160 extends across the lap of the occupant, as in an arrangement likethat shown in FIG. 21. In use, the chamber 191 positioned in contactwith the occupant is first inflated and the remaining chamber 192 orchambers are subsequently inflated, thereby assisting to position theoccupant in a preferred upright posture in the event of a collision whenthe occupant is not sitting upright.

[0096] In another embodiment of a seamless tubular textile structure, avertically adjustable fan-shaped weaving reed or guide 90 like thatshown in FIG. 13, or such as is described in WO 96/31643 to Büsgen, isemployed to assist the narrowing or spreading of the warp yarns. Thefan-shaped reed pieces are moved together as a unit so that a verticalshift in weaving reed position causes a narrowing or spreading of thelateral spacing of the warp members. In practice, the fan-shaped reed 90is positioned dependent on the particular weft in the predeterminedtextile pattern thereby causing the warp members to become more or lessdensely packed. A programmed computer or microprocessor may be employedto control the position of the fan-shaped reed. The less densely packedwarp members result in a wider textile width, and thus larger cavitysize or diameter, and the more densely packed warp members result in anarrower textile width and thus smaller cavity size or diameter.

[0097] Elements of a suitable weaving apparatus 240 are shownschematically in FIG. 23. The warp yarns 241 are drawn from warp beam242 over letoff guide roll 243 through the eyes of heddles 244 andfan-shaped weaving reed 245 by takeup roll 250. In practice in themanufacture of a single cavity hollow textile, there are four groups ofwarp yarns, two for the upper layer of the hollow textile and two forthe lower layer of the hollow textile, although only two are observable.The spacing of the warp yarns 241 in the shed is controlled by theposition of fan-shaped reed 245 which as shown may be moved upward ordownward or toward or away or combinations of these movements relativeto the heddles to vary the spacing of the warp yarns 241 as the shuttle246 containing a bobbin 247 of weft yarn 248 is passed through the shed.The weaving apparatus 240 is equipped with selvedge guides 249 whichgrip the selvedges of the newly formed hollow textile 251 and guide itto the takeup roll 250. The position of the selvedge roller guides 249is varied in correspondence to the warp spacing as determined by theposition of the fan-shaped reed 245. For simplicity of illustration, theharnesses for vertical movement of the heddles are not shown, as theseare well known to those of ordinary skill in the textile art.

[0098] In another embodiment of a seamless tubular textile structure, aweaving guide having laterally movable warp guide members (notillustrated) is employed. Alternatively, an actively working adjustmentcan be used that laterally directs and positions the warp members.

[0099] For use in inflatable belt assemblies, seamless hollow or tubulartextile structures can be produced as a continuous member of changingcavity size, the pattern being periodically repeated as shown in FIGS.19, 20 and 22 as desired for the required inflatable belt portion 112,160, and subsequently severed in the smaller cavity portions to providea plurality of like inflatable members. Alternatively, individualseamless hollow or tubular textile structures of changing cavity sizecan be produced one at a time, the weaving pattern being repeated afterseverance of the preceding completed structure.

[0100] In certain embodiments, as shown in FIGS. 20 and 22, the seamlesshollow textile structure 200 and 220 respectively is manufactured withplastically extensible filaments 202 (partially oriented yarn) in apredetermined portion of the warp members and weft members. Where suchplastically extensible filaments are employed, any excessive stress thatwould otherwise arise during inflation may be absorbed by drawing ofsuch plastically extensible filaments to produce a larger inflated shape224 as shown in dashed lines in FIG. 22 in the event that the internalgas pressure exceeds a predetermined threshold value that otherwisemight cause tearing of the fabric of the inflatable belt portion. TypeN13 nylon available from DuPont having an elongation of 300 or morepercent is an example of a plastically extensible filamentary materialthat can be used. Yarns of different degrees of plastic extensibilitymay be employed in the manufacture of the hollow textile structure foruse in a restraint system of the invention. Unstabilized yarns may beused at weaving in selected or all locations to allow shrinkage insubsequent treatment operations to tighten the weave. In contrast, theremainder of the hollow textile structure is formed of higher tensileyield point yarns that have a much lower elongation capability, e.g.about 20 percent.

[0101] As shown in FIG. 19, the seamless hollow textile structure 200,includes first hollow end portion 201 and second hollow end portion 203that are joined by integral weaving to center portion 204. The number ofwarps 205 is constant throughout the length of textile structure 200,but the number of wefts 206 per unit of length is greater adjacent endportion 203 than adjacent end portion 201. The wefts in portion 208 aremore closely spaced than the wefts in the remainder of the hollowtextile structure 200.

[0102] As shown in FIG. 20, the seamless hollow textile structure 210,includes first hollow end portion 211 and second hollow end portion 213that are joined by integral weaving to center portion 214. The number ofwarps 205 is varied throughout the length of textile structure 210, withadditional warps 216 being provided in proportion to the increase insize (circumference) of the hollow textile structure. The number ofwefts 206 per unit of length is greater adjacent second end portion 213than adjacent first end portion 211. The cross-sectional configurationof second end portion 213 changes from a hollow woven to a flat wovenconstruction that is not inflatable as the distance from the centerportion 214 increases.

[0103] As shown in FIG. 22, the seamless hollow textile structure 220,includes first hollow end portion 221 and second hollow end portion 223that are joined by integral weaving to center portion 225. The number ofwarps 205 is varied throughout the length of textile structure 220, withadditional warps 216 being provided in proportion to the increase insize (circumference) of the hollow textile structure. The number ofwefts 206 per unit of length is greater adjacent second end portion 223than adjacent first end portion 221. The cross-sectional configurationof second end portion 223 changes from a hollow woven to a flat wovenconstruction 229 that is not inflatable as the distance from the centerportion 225 increases. The wefts 206 in portion 228 are more closelyspaced than the wefts in the remainder of the hollow textile structure220, and are formed of plastically extensible yarn 202 that has agreater elongation at breakage than the elongation at breakage of thewefts in the remainder of the hollow textile structure 220.

[0104] A suitable tapered seamless tubular textile structure suitablefor use in an inflatable belt assembly according to the invention may beof the following parameters. The length of the textile structure for theinflatable belt portion is typically from about 50 to about 75 inches,the width in the narrowest section at each end when flattened is 2.25inches which corresponds to an inflated diameter in the end portionsabout 1.4 inches, and the width in the widest section between the spacedend portions when flattened is about 9 inches which corresponds to aninflated diameter in the largest section of about 5.7 inches. The warpsmay be formed of a 280 denier, 34 filament, Type 728 nylon availablefrom E. I. duPont de Nemours & Company, Wilmington, Del. (DuPont), USA.According to DuPont, Type 728 nylon yarn with a twist of 3 turns perinch (1t/cm) has an elongation at break of about 21.8 percent. The weftmay be formed of 420 denier, 68 filament, Type 743 nylon available fromDuPont. According to DuPont, Type 743 nylon yarn with a twist of 3 turnsper inch (1t/cm) has an elongation at break of about 19 percent. Thetextile includes 1276 warp ends spaced around the circumference,although it is believed that the number of warp ends can be increased toabout 1400 for improved performance. The textile includes weft membersup to a maximum of 71/inch (28/cm), although this number is believed tobe greater than is necessary to withstand the hoop stress duringinflation. The weave pattern is a variation of a plain weave that isdescribed as a 4×4 filling rib pattern (so called because ribs areproduced in the filling direction during weaving). Shown in FIGS. 17 and18 is another preferred weaving pattern for an inflatable textilestructure of the invention. As shown in FIG. 17, the weft ends 230 arepaired and as shown in FIG. 18, the warp ends 232 are in groups of fourin the textile structure. Following weaving, the textile structure maybe scoured to remove any processing oils and sizings, and to improvedyeing and adhesion of a coating, if provided, to improve retention ofthe inflation gas.

[0105] In certain embodiments where the inherent resistance to gaspermeability of the fabric of the inflatable belt portion isinsufficient to allow the inflated belt portion to retain its inflatedconfiguration for a sufficient time after a collision, a coating isapplied to the fabric of the inflatable belt portion to reduce gaspermeability relative to that of an uncoated fabric. It is believed thata coating is not required in every application.

[0106] Alternatively, a tapered seamless tubular textile structuresuitable for use in an inflatable belt assembly according to theinvention may be formed as set forth above, except the textile structureis formed of polyester as described hereinafter. The warp member may beformed of 440 denier, 100 filament, Type 52 (low elongation) polyesterfrom DuPont. The weft member may be formed of 440 denier, 100 filament,Type 68 (high tenacity) polyester from DuPont. The weave pattern may bea 4×4 filling rib pattern as described above.

[0107] For use in an inflatable seat belt assembly, the seamless tubulartextile structure is pleated, e.g. using a “W” fold pattern as shown inFIG. 6 in order to reduce the width to that of typical restraintwebbing. The number of pleats is dependent upon the width of the textilestructure before pleating and the desired width after pleating. Thepleating process may be assisted by insertion of metal strips into thetextile structure to facilitate folding of the textile structure to thedesired width. When the pleating is complete, the resultant inflatabletextile band is pressed with a hot press similar to those that are usedto press apparel.

[0108] The pleated textile structure is then covered with a tubularcover that is weaker in a direction corresponding to the weft directionof its associated inflatable (pleated) portion so that upon inflationthe cover tears away and allows the inflatable structure to inflate tofull dimension. The cover may be color coordinated for aestheticpurposes. There are numerous ways to accomplish controlled tearing awayof the cover during inflation of the inflatable belt portion 104, 160.The cover can be sewn from a strip of fabric that is joined at its endsas by stitching 109 to encapsulate the inflatable belt portion as shownin FIG. 9. Suitable fabric for a sewn cover 105 is available fromPrecision Fabrics Group, Greensboro, North Carolina, as style number54516. Alternatively, the cover can be woven as a tubular member that isslipped over the pleated inflatable belt portion. A suitable woventubular cover is available from Breed of Knoxville, Tennessee. The woventubular cover may be designed and manufactured to be frangible, forexample, through use of weaker yarns at selected locations or byinducing weakness by mechanical action or by a laser. Upon inflation ofthe inflatable belt portion 104, the cover cleaves along thepredetermined weakness thereby allowing the inflatable to progressivelyinflate to its full dimension.

[0109] The inflatable belt portion 104 may be protected against theinflux of the inflation gas, particularly if the gas is hot enough todegrade the fabric of inflatable belt portion 104, with a fabric shield150 (dashed lines in FIG. 4) that is attached to the gas outlet of theinflator 10 and inserted into the inflatable belt portion. Theconcentrically arranged fabric shield 150 and hollow belt portion 104may be affixed to the gas outlet of the inflator 10 as by a clamp orswaged metallic ring. The internal fabric shield 150 may be formed ofsilicone-coated 630 denier nylon fabric available from Milliken Companyof Spartanburg, S.C. that is woven into a tube of about 1.75 inchdiameter by about 37 inches long having a end 151 that is configured tobe attached to the gas inlet. The internal fabric shield 150 insulatesthe inflatable belt portion from the hot inflation gas and therebyminimizes the potential of damage to the inflatable textile structure ofthe inflatable belt portion. An internal fabric shield is not requiredfor all embodiments of the inflatable belt portion 104. For thoseembodiments of an inflatable belt portion that are inherentlysufficiently strong to resist rupture due to rapid inflation with aheated gas, no internal fabric shield is needed. For those embodimentsof an inflatable belt portion that are not inherently sufficientlystrong to resist rupture during rapid inflation, an internal fabricshield or other thermal insulation is needed. In practice, for the sameinflatable belt portion, this may be dependent upon the source ofinflation gas. Where the gas source produces gas at a relatively hightemperature that could degrade the material from which the inflatablebelt portion is formed, an internal fabric shield is recommended toprotect the inflatable belt portion. Where the gas source does notproduce gas at a relatively high temperature that could degrade thematerial from which the inflatable belt portion is formed, an internalfabric shield is not needed. However, such an internal fabric shield canbe employed to locally strengthen the inflatable belt portion to resistthe shock of rapid inflation, thereby enabling use of a lighter andweaker fabric for the main tube of the inflatable belt portion.

[0110] Inflatable belt assemblies are costly. It is accordinglydesirable that the unitary belt 100 becomes inflated only when it isintended to be used. To accomplish this, a switch 144 (FIG. 5) may bedisposed in the retainer 122 at a position where the coupling member iscoupled to the retainer 122. The switch 144 is closed only when thecoupling member 116 is coupled to the retainer 122. The switch 144 isconnected in a circuit with the connector pins 24 in FIG. 2. As aresult, the inflator 10 is actuated to obtain combustion of thepyrotechnic material 30 only when the switch 144 is closed. Thisprevents the inflatable belt portion 104 from being inflated except whenthe occupant intends to obtain the protection provided by the unitarybelt 100.

[0111] The system constituting this invention has certain importantadvantages in its individual sub-systems and in its assemblyrelationship. For example, the inflator 10 provides an almostinstantaneous opening of the container 32 (FIGS. 1 and 2) and inflationof the inflatable belt portion, the composition of the pyrotechnicmaterial 30 produces environmentally friendly gas, and there are aminimal number of components in the inflator 10. The inflator 10 of thisinvention also provides for substantially uniform operatingcharacteristics in the unitary belt 100 even with considerable changesin the ambient temperature in the vicinity of the vehicle. Where theinflatable belt portion has multiple chambers (FIGS. 15 and 16) that aresequentially inflated, greater protection of the occupant is possiblethan in the past. Where the inflatable belt portion is provided withwarps 194 of increased strength (FIG. 16), rupture of the inflatablebelt portion will not result in loss of restraint.

[0112] The unitary belt 100 also has certain important advantages. Whenthe inflatable belt portion 104 becomes inflated, it protects theoccupant's chest, neck and head. It also tightens the lap belt portion112 against the occupant across the occupant's lap. This providesadditional protection for the occupant's lower extremities. When theoccupant desires to enter or exit the occupant door 110, the couplingmember 116 is detached from the retainer 122 and the lap belt portion112 becomes disposed (e.g. wound) on the retractor 124. This disposesthe inflatable belt portion 104 substantially along the seat 108 at aposition to the rear of the door 110 as shown in FIG. 8.

[0113] The system constituting this invention also has other advantagesover the prior art. For example, the housing 12 is disposed adjacent theopening 40 and the optional conduit 42. This helps to minimize the timefor the inflatable belt portion 104 to become inflated. It alsominimizes the weight of the inflator 10 and the space occupied by theinflator. The minimization in the weight of the inflator 10 and thespace occupied by the inflator also minimizes the amount of thepyrotechnic material 30 in the inflator. The combustion of thepyrotechnic material 30 produces by-products and end products that donot require a filter to be included in the inflator.

[0114] The system of this invention is also advantageous in thedisposition of the cover 105 (FIG. 9) in enveloping relationship to theinflatable belt portion 104 to protect the inflatable belt portion andcontrol the inflation of the inflatable belt portion. The system is alsoadvantageous in disposing the switch 144 in the retainer 122 to providefor the operation of the system only when the switch is closed by thedisposition of the coupling member 116 in the retainer.

[0115] Although this invention has been disclosed and illustrated withreference to particular embodiments, the principles involved aresusceptible for use in numerous other embodiments that will be apparentto persons skilled in the art. Although the invention has been shown anddescribed with respect to a certain preferred embodiment or embodiments,it is obvious that equivalent alterations and modifications will occurto others skilled in the art upon the reading and understanding of thisspecification and the annexed drawings. In particular regard to thevarious functions performed by the above described integers (components,assemblies, devices, compositions, etc.), the terms (including areference to a “means”) used to describe such integers are intended tocorrespond, unless otherwise indicated, to any integer which performsthe specified function of the described integer (i.e., that isfunctionally equivalent), even though not structurally equivalent to thedisclosed structure which performs the function in the hereinillustrated exemplary embodiment or embodiments of the invention. Inaddition, while a particular feature of the invention may have beendescribed above with respect to only one of several illustratedembodiments, such feature may be combined with one or more otherfeatures of the other embodiments, as may be desired and advantageousfor any given or particular application.

[0116] In addition, the invention is considered to reside in allworkable combinations of features herein disclosed, whether initiallyclaimed in combination or not and whether or not disclosed in the sameembodiment. The invention is, therefore, to be limited only as indicatedby the scope of the appended claims.

What is claimed is:
 1. In a combination for protecting an occupant in avehicle in the event of a collision involving the vehicle, the vehicle(102) having a support structure (106, 125) and having a seat (108) forthe occupant with an inboard side and an outboard side and having afirst retainer means (122) at the inner side of the occupant's seat andhaving second retainer means (124) at the outer side of the occupant'sseat, a unitary belt (100) including an inflatable belt portion (104)and a lap belt portion (112), the inflatable belt portion (104)extending diagonally across the chest of the occupant, the inflatablebelt portion having first and second opposite ends and being constructedto be attached at the first end to the support structure (106) in thevehicle (102), the inflatable belt portion comprising a seamless hollowtextile structure (200, 210, 220), the lap belt portion (112) havingfirst and second ends and being attached at the first end to the secondend of the inflatable belt portion and extending across the lap of theoccupant from the second end of the inflatable belt portion (104), thesecond end of the lap belt portion having a coupling member (116) forcoupling to the first retainer means (122) in the vehicle, the lap beltportion (112) having a second coupling member at a position near theinflatable belt portion for coupling to the second retainer means (124)in the vehicle, and means (124, 116) operatively coupled to the lap beltportion (112) for extending the lap belt portion upwardly in thedirection of the inflatable belt portion (104) and for providing for atightening of the lap belt portion against the lap of the occupant whenthe inflatable belt portion becomes inflated.
 2. In a combination as setforth in claim 1, wherein the textile structure (104, 112, 160, 220,210, 220) is a continuously woven member that is pleated prior toinflation.
 3. In a combination as set forth in claim 1, wherein thetextile structure (104, 112,160, 220, 210, 220) is a continuously wovenmember of varying diameter when inflated, the textile structure having acenter portion (204, 214, 225) between first end portions (201, 211,221) and second end portions (203, 213, 223), the inflated diameter ofthe end portions being less than that of the center portion, the firstend portion being constructed to be attached to the support structure(106, 125) in the vehicle (102), and the second end portion beingconstructed to be attached to the lap belt portion (112, 160).
 4. In acombination as set forth in claim 1, wherein the textile structure (104,112, 160, 220, 210, 220) is a continuously woven member of varyingdiameter when inflated, the textile structure having first end portions(201, 211, 221) and second end portions (203, 213, 223) and a centerportion (204, 214, 225), the diameter of the end portions being lessthan that of the center portion, the number of warp ends (205, 216) perunit of textile circumference decreasing as the diameter of the textilestructure increases, the first end portion being constructed to beattached to the support structure (106, 125) in the vehicle (102).
 5. Ina combination as set forth in claim 1, wherein the textile structure(104, 112, 160, 220, 210, 220) is a continuously woven member havingfirst end portiosn (201, 211, 221) and second end portions (203, 213,223) joined to a center portion (204, 214, 225), at least some of theweft members (206) adjacent the second end portion being of plasticallyextensible filamentary material (202).
 6. In a combination as set forthin claim 1 wherein the inflatable textile structure (104, 112, 160, 220,210, 220) is a continuously woven member having a portion (228) that isplastically expansible in diameter without rupture in response toinflation gas pressure in excess of a predetermined value
 7. In acombination as set forth in claim 6, wherein the inflatable textilestructure (104, 112, 160, 220, 210, 220) has a first end portion (201,211, 221) and a second end portion (203, 213, 223) which are resistantto increase in diameter when inflated in response to inflation gaspressure in excess of a predetermined value and a center portion (204,214, 225) which plastically expands in diameter without rupture inresponse to inflation gas pressure in excess of said predeterminedvalue.
 8. In a combination as set forth in claim 6, wherein theinflatable textile structure (104, 112, 160, 220) has a first endportion (221) and a center portion (225) which are resistant to anincrease in diameter when inflated in response to inflation gas pressurein excess of a predetermined value and a second end portion (228) whichplastically expands in diameter without rupture in response to inflationgas pressure in excess of said predetermined value.
 9. In a combinationas set forth in claim 1, wherein the textile structure (104, 112, 160,200, 210, 220) is a continuously woven member of varying diameter, thetextile structure having first end portions (201, 211, 221) and secondend portions (203, 213, 223) and a center portion (204, 214, 225), thediameter of the end portions when inflated being less than that of thecenter portion when inflated, the center portion extending diagonallyacross the chest of the occupant.
 10. In a combination as set forth inclaim 1, wherein the textile structure (104, 112, 160, 200, 210, 220) isa continuously woven member of varying diameter, the textile structurehaving first end portions (201, 211, 221) and second end portions (203,213, 223) and a center portion (204, 214, 225), the diameter of the endportions when inflated being less than that of the center portion wheninflated, the center portion extending diagonally across the chest ofthe occupant and across the outboard side of the neck and the head ofthe occupant.
 11. In a combination for protecting a human occupant in avehicle (102) in the event of a collision involving the vehicle, thevehicle having a support structure (106, 125) and having a seat for theoccupant with an inboard side and an outboard side, a unitary belt (100,160) including an inflatable belt portion (104, 160) comprising aseamless hollow textile member (180, 200, 210, 220) extending across thebody of the occupant, the inflatable belt portion (104, 160, 180) havingfirst and second opposite ends extending between the inboard side andthe outboard side of the seat (108) and being constructed to be attachedto the support structure (106, 125) in the vehicle (102), theconstruction of the inflatable belt portion providing for a tighteningof the belt against the occupant when the inflatable belt portionbecomes inflated, and inflator means (10) disposed relative to the firstend of the inflatable belt portion providing gas inflation of theinflatable belt portion when the vehicle is in a collision.
 12. In acombination as set forth in claim 11, wherein the seamless hollowtextile member (180, 200, 210, 220) is a continuously woven member thatis pleated prior to inflation.
 13. In a combination as set forth inclaim 12, wherein the pleated textile member (104) is encased in afrangible cover (105) that is ruptured upon inflation of the pleatedtextile member.
 14. In a combination as set forth in claim 11, whereinthe inflatable textile member (180, 200, 210, 220) is a continuouslywoven member which is of varying size along its length when inflated,the inflatable textile member having first end portions (201, 211, 221)and second end portions (203, 213, 223) joined to a center portion (204,214, 225), the inflated size of the end portions being less than that ofthe center portion.
 15. In a combination as set forth in claim 11,wherein the inflatable textile member (180, 200, 210, 220) is acontinuously woven member that is of varying size along its length wheninflated, the number of warp ends (205, 216) per unit of textilecircumference decreasing as the size of the textile member increases.16. In a combination as set forth in claim 11, wherein the inflatablebelt portion (104, 160) includes an integrally woven stiffener (193)comprising larger warp members (194) that contact the occupant andresist twisting of the inflatable belt portion and carry most of theload when the belt is tensioned in a collision.
 17. In a combination asset forth in claim 11, wherein the inflatable belt portion (104, 160,180, 190) contains at least two integrally woven chambers (181, 182,191, 192) that are inflatable.
 18. In a combination as set forth inclaim 17, wherein one of the chambers (181, 191) is first inflated andanother of the chambers (182, 192) is subsequently inflated by gaspassing from said one chamber (181, 191).
 19. In a combination as setforth in claim 11, wherein the inflatable belt portion (104, 160, 180,190) contains at least two integrally woven inflatable chambers (181,182, 191, 192) are sequentially inflatable.
 20. In a combination as setforth in claim 11, wherein the inflatable textile member (200, 210, 220)is a continuously woven member that is of varying size along its lengthwhen inflated, the number of weft ends (206) per unit of textile lengthincreasing as the size of the textile member increases.
 21. In acombination as set forth in claim 20, wherein the number of weft ends(206) per unit of textile length is greater in the center portion (204,214, 225) than in the end portions (201, 211, 221, 203, 213, 229) of theinflatable textile member.
 22. In a combination as set forth in claim20, wherein the center portion (214, 225) includes a greater number ofwarps (205, 216) than the end portions (211, 213, 221, 223) of theinflatable textile member.
 23. In a combination as set forth in claim20, wherein the center portion (204) includes the same number of warps(205) as the end portions (201, 203) of the inflatable textile member(200).
 24. In a combination as set forth in claim 20, wherein at leastsome of the weft members (206) of the center portion (214. 225) of theinflatable textile member (210, 220) are of plastically extensiblefilamentary material (202).
 25. In a combination as set forth in claim11, wherein the inflatable textile member (210, 220) is a continuouslywoven member having a portion (214, 224) that is plastically expansiblein size without rupture in response to inflation gas pressure in excessof a predetermined value that does not cause substantial plasticexpansion of the remainder of the inflatable textile member.
 26. In acombination as set forth in claim 20, wherein the inflatable textilemember (210. 220) has a first end portion (211, 221) which does notsubstantially increase in size when inflated in response to inflationgas pressure in excess of a predetermined value and a second end portion(224) which plastically expands in size without rupture in response toinflation gas pressure in excess of said predetermined value.
 27. In acombination as set forth in claim 20, wherein the inflatable textilemember (220) has a first end portion (221) and a second end portion(223) which are resistant to increase in size when inflated in responseto inflation gas pressure in excess of a predetermined value and acenter portion (225, 224) which plastically expands in size withoutrupture in response to inflation gas pressure in excess of saidpredetermined value.
 28. In a combination as set forth in claim 11,wherein the textile member (180, 200, 210, 220) is a continuously wovenmember that varies in size along its length when inflated, the textilemember having first end portions (201, 211, 221) and second end portions(203, 213, 223) joined to a center portion (204, 214, 224), the size ofthe end portions when inflated being less than that of the centerportion when inflated, the center portion extending diagonally acrossthe chest of the occupant.
 29. In a combination as set forth in claim11, wherein the textile member (180, 200, 210, 220) is a continuouslywoven member of varying size, the textile member having first endporitons (201, 211, 221) and second end portions (203, 213, 223) joinedto a center portion (204, 214, 225), the size of the end portions wheninflated being less than that of the center portion when inflated, thecenter portion extending diagonally across the chest of the occupant andacross the outboard side of the neck and the head of the occupant. 30.In a combination as set forth in claim 11, wherein the textile member(180, 200, 210, 220) is a continuously woven member that varies in sizealong its length when inflated, the textile member having first endportions (201, 211, 221) and second end portions (203, 213, 223) joinedto a center portion (204, 214, 225), the size of the end portions wheninflated being less than that of the center portion when inflated, thecenter portion extending across the lap of the occupant.
 31. In acombination as set forth in claim 30, further including a couplingmember (116) affixed to an end of the belt (112) and a retainer means(122) in the vehicle (102) for detachably receiving the coupling member,wherein the inflator means (10) is disposed within the inflatable beltportion and is electrically coupled to receive a triggering signal whenthe belt is coupled to its retainer means.
 32. In a combination as setforth in claim 31, wherein the inflator means (10) is disposed adjacentthe end of the belt to be detachably coupled to its retainer.
 33. In acombination as set forth in claim 31, further including a retractor(124) for minimizing slack in the belt portion (112, 104) and forpreventing the length of the belt portion from increasing when a forceabove a predetermined value is imposed on the belt portion forincreasing the length of the belt portion, wherein the inflator means(10) is disposed between the retractor (124) and the end of the belt tobe detachably coupled to its retainer means (122).
 34. In a combinationas set forth in claim 30, further including length adjustment andlocking means (124) positioned under the seat (108) operably connectedto the lap belt portion (112) for adjustment of the length of the lapbelt portion and for providing for a tightening of the lap belt portionagainst the lap of the occupant when the inflatable belt portion (104,160) becomes inflated, wherein the belt extends beneath the seat, andthe inflator means (10) is disposed between the length adjustment means(124) and the end of the belt to be detachably coupled to its retainer(122).
 35. In a combination as set forth in claim 30, wherein theinflator means (10) is disposed externally of the inflatable beltportion (104, 160).
 36. In a combination for protecting an occupant in avehicle (102) in the event of a collision involving the vehicle, thevehicle having a support structure (106, 125) and having a seat (108)for the occupant with an inboard side and an outboard side and having afirst retainer means (122) at the inner side of the occupant's seat andhaving second retainer means (124) at the outer side of the occupant'sseat, a unitary belt (100) including a lap belt portion (112) and aninflatable belt portion (104), the lap belt portion (112) being disposedto extend across the lap of the occupant and having a first end forattachment to the first retainer (122), the lap belt portion having asecond end opposite the first end, the inflatable belt portion (104)extending diagonally across the chest of the occupant, the inflatablebelt portion having first and second opposite ends and being constructedto be attached at the first end to the support structure in the vehicle(106), the inflatable belt portion comprising a seamless hollow textilemember (180, 200, 210, 220), the inflatable belt portion (104) beingattached to the lap belt portion (112) at the second end of the lap beltportion, means disposed at the second end of the lap belt portion (112)for coupling to the second retainer (124) and for guiding the lap beltportion to the inflatable belt portion, means disposed at the second endof the inflatable belt portion (104) for attaching the inflatable beltportion to the support structure, and a retractor (124) disposedrelative to the lap belt portion near the second coupling member forminimizing slack in the lap belt portion upon attachment of the firstcoupling member to the first retainer (122) and for preventing thelength of the lap belt portion from increasing when a force above apredetermined value is imposed on the lap belt portion for increasingthe length of the lap belt across the lap of the occupant.
 37. In acombination for protecting an occupant in a vehicle (102) in the eventof a collision involving the vehicle, the vehicle having a supportstructure (106, 125) and having a seat (108) connected to the supportstructure (125) for the occupant with a first side and a second side andhaving a first retainer means (122) at the first side of the occupant'sseat and having second retainer means (124) at the occupant's seat, aunitary belt (100) including an inflatable lap belt portion (112, 160)comprising a seamless hollow textile member (180, 200, 210, 220), theinflatable lap belt portion (112, 160) being disposed to extend acrossthe lap of the occupant and having a first end affixed to a firstcoupling member (116) for detachable attachment to the first retainermean (122), the lap belt portion (112) having a second end opposite thefirst end coupled to the second retainer means (124), guide means (103)for guiding the lap belt portion (112) from the second side of the seatto extend across the lap of the occupant, a retractor (124) disposedrelative to the lap belt portion (112, 160) for minimizing slack in thelap belt portion upon attachment of the first coupling member (116) tothe first retainer means (122) and for preventing the length of the lapbelt portion from increasing when a force above a predetermined value isimposed on the lap belt portion for increasing the length of the lapbelt across the lap of the occupant, and inflator means (10)disposedrelative to the inflatable belt portion providing gas inflation of theinflatable belt portion when the vehicle is in a collision.
 38. In acombination as set forth in claim 37, wherein the retractor (124) andthe inflator means (10) are disposed under the seat (108).
 39. In acombination for protecting an occupant in a vehicle (102) in the eventof a collision involving the vehicle, the vehicle having a supportstructure (106, 125) and having a seat (108) connected to the supportstructure (125) for the occupant with a first side and a second side andhaving a first retainer means (122) at the first side of the occupant'sseat and a second retainer means (103) at the second side of theoccupant's seat, a unitary belt (112) including an inflatable lap beltportion (160) comprising a seamless hollow textile member (160, 180,200, 210, 220), the inflatable lap belt portion (160) being disposed toextend across the lap of the occupant and having a first end affixed toa first coupling member (116) for detachable attachment to the firstretainer means (122), the lap belt portion having a second end oppositethe first end coupled to the second retainer means (103, 124), guidemeans (103) for guiding the lap belt portion (112, 160) from the secondside of the seat to extend across the lap of the occupant, and aretractor (124) disposed at the second side of the seat for minimizingslack in the lap belt portion upon attachment of the first couplingmember to the first retainer means and for preventing the length of thelap belt portion from increasing when a force above a predeterminedvalue is imposed on the lap belt portion for increasing the length ofthe lap belt across the lap of the occupant, and inflator means (10)disposed relative to the inflatable belt portion providing gas inflationof the inflatable belt portion when the vehicle is in a collision. 40.In a combination as set forth in claim 36, wherein the inflatable beltportion (160, 180, 200, 210, 200) is integrally woven with the lap beltportion (160).
 41. In a combination as set forth in claim 36, whereinthe inflatable belt portion (190) includes an integrally woven stiffener(193) that resists twisting of the inflatable belt portion.
 42. In acombination as set forth in claim 36, wherein the inflatable beltportion (190) includes an integrally woven stiffener (193) comprisinglarger warp members (194) that contact the occupant and resist twistingof the inflatable belt portion and carry most of the load when the beltis tensioned in a collision.
 43. In a combination as set forth in claim36, wherein the inflatable belt portion (160, 180, 190) contains atleast two integrally woven chambers (181, 182, 191, 192) that areinflatable.
 44. In a combination as set forth in claim 43, wherein oneof the chambers (181, 191) is first inflated and another of the chambers(182, 192) is subsequently inflated by gas passing from said one chamber(181, 191).
 45. In a combination as set forth in claim 37, wherein theinflatable belt portion (160, 180, 190) contains at least two integrallywoven inflatable chambers (181, 182, 191, 192) are sequentiallyinflatable.